A Sustained Release of Model Drug from a Novel Polyacrylic Acid-polyaluminium Chloride Superabsorbent

Anew kind of drug loaded superabsorbent polymer was prepared and theproperties of drug delivery performance are reported in the current study. Thesuperabsorbent polymer was prepared via a process in which polyacrylic acid(PAA) was cross-linked via complex formation with polyaluminium chloride (PAC)through AlCl3 hydrolysis under alkaline conditions followed by freeze drying. The drugswere loaded into the network structure of the superabsorbent during the complexformation of cross-linking process. The new drug loaded superabsorbents wereprepared aiming to overcome the drawbacks of those prepared via conventionalmethod. The loading as well as the sustained release of the model drug acetaminophen(AMP) using the prepared superabsorbent has been studied by UV-absorptionspectroscopy, and compared with superabsorbent prepared via conventional freeradical polymeri-zation method. It was found that the AMP loaded before complexformation of cross-linking process and showed a much better loading performance anddrugs sustained release properties compared to the product with which AMP wasadded during the process of complex formation of cross-linking process. The drugrelease mechanism has been analyzed for the polymers with different cross-linkingdensities via numerical simulation based on different kinetic models as well as theRitger-Peppas equation. At the same time, it is found that the AMP release rate at pH4 is initially greater than that at pH 10 and release rate increases as temperature isincreased.